Negative Effect of Rate Response on someone with Pacemaker Syndrome

I've had my ICD now (on my third one now, a CRT-D) for 10 years.  It did it's job with a few shocks early on but VT is fortunately mostly a thing of the past.  However over the last 5 or so years I've become quite symptomatic (low blood pressure, syncope) when BiV paced during activity.   I thought is was just progression of cardiomyopathy but I couldn't get out of my mind that it was pacemaker induced (I had all  the classic symptoms of Pacemaker Syndrome).  Before my last implant I complained enough to my EP that he did the switch to the CRT-D which helped for a bit but over time the symptoms recurred and got worse to the point when I stood up and walked briskly or up stairs BP would drop to <70 or so, and if I didn't lean or sit it was lights-out.  I would almost always get that "pacing" sensation like you do when the tech speeds up your heart on device checks immediately prior to the drop in blood pressure so that became a warning.  Would get same sensation when riding over a rough road or riding lawnmower. 

After almost fainting while walking into last EP appt. he made three changes: (1) turned off LV (BiV)pacing, (2) extended AV delay to 250 (from 180) and (3) turned off my rate respoonse.  RVPacing went from 95% to 3%, It's been a few days now and I feel like a totally new person.  I'm not parinoid about standing and walking while waiting to see if BP would drop, and the fatigue and fear has gone. I feel NORMAL!!  I still can feel when my RV is paced, but it's usually when lying or sitting,  I'll fill in some more details and add some questions to the forum members later but for the time being I want everyone to be aware that in my case, that wonderful little accelerometer in my PM has been making my life miserable.

2 Comments

Accelerometer vs Minute Ventilation

by steppingstones - 2019-05-24 00:18:47

I have had a pacemaker for over 40 years and was so very grateful when I was introduced to a new model with minute ventilation (2007) and was able to have the accelerometer turned off.  I purchased a Polar fitness monitor to prove to the doctor it was the bumpy roads, riding in a truck or believe it or not even stuffing envelopes at work which was causing me to not feel good. 

When there was a recall a few years back on the minute ventilation software and they turned off that feature and they had to turn on the accelerometer again I was miserable.  I kept calling the manufacturer (Boston Scientific) for updates.  Fast forwarding……currently

I have a CRT-P and yes I use the minute ventilation, however on the old device there were sensitivity settings for the minute ventilation.  My current CRT-P still Boston Scientific has only an ON or OFF for minute ventilation no sensitivity setting.  The accelerometer is turned off, but we are discussing a trial of turning it on but very low sensitivity due to my heart rate stays so low. My EP says the blending of the two is the best.

So glad you found the problem and feeling better. 

Taking rate response for granted?

by John@PC - 2019-05-27 18:57:00

Do we take Rate Response settings for granted?  It sounds like you're not SteppingStones but I certainly did to my detriment.  If you're reading this and (1) have an accelarometer sensor with Rate Response active, and (2) have the symptoms described above, I would recommend you consult your EP about it and whether or not disabling the rate response would be an option to try. I developed my own "test" where I would take my BP sitting, then standing for a minute, then after walking rapidly or up stairs which (along with having that "pacing" sensation and coming close to passing out) convinced me it was RR related   

You know you're wired when...

You have rhythm.

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Sometimes a device must be tuned a few times before it is right. My cardiologist said it is like fine tuning a car.